Bullets: Mass vs. Speed

Demolition Ranch continues to produce excellent videos: firearms-related destruction that’s as entertaining as it is informative. As someone who owns both a .44-caliber revolver or two and a Smith & Wesson .500-firing Big Horn Armory lever gun and spends time in bear country, this video is of special interest. I’ve always been a fan of overkill. This is it.

Wow. I thought my .454 was punishing. Now I know why I see so many of these 500’s for sale with “only 6 shot’s fired thru it” Did you see the black hole created by the 700 gr bullet? (no really, watch the video) Now we need a hard cast 700 gr. cause the 454 in hard cast 300gr I think will go 44 inches in gel. This thing would prob do 72.

You talking about that little shockwave that puffed through the smoke on the body armor test? Do you think that was from the muzzle blast or from that massive 700gr flatpoint tearing a hole in the universe as it went down range? He pointed it out in the video but didnt mention what it might have been.

I would love to see a TTAG post by a physicist who can really explain the two concepts and how they relate to our decisions on bullet weights and caliber choices, and how those variables affect things like recoil, penetration, large game stopping power, etc.

Bullet construction plays a big part in it. A JHP will deform and penetrate less due to drag on the body. There have been studies trying to treat the body as a fluid, and use fluid mechanics to make predictions, but have not been too successful. The best method we currently have is to shoot simulated tissue, and study bullet wounds from hospitals and hunters.

Bullet construction, bullet density, sectional density, ballistic coefficient and other variables are things we ultimately make choices on. But I suggest those choices would be folly without a foundation understanding of momentum and kinetic energy.

We would do well to learn the laws of physics, and we have to start somewhere.

Also, dont forget that bullets spin to stabilize, and this bullet is too long to stay point first in a target. So it will tumble end over end, leading to less penetration in a hard medium, but a larger wound channel if the target is soft.
Far too many variables to use models or calculations to figure anything out. Much better to shoot goats and go by observed results like Hatcher did…

Not just because of that, but also because part of the energy goes into deforming the bullet itself. It’s why Lehigh Xtreme Penetrator achieves deep penetration and wide wound channels – because the bullet it solid and doesn’t deform, and the mechanism it uses to create that wide wound channel is different from JHP, it has that much more energy to keep going deeper.

The energy output is the same as the energy input minus loss; with the same charge, the differences in input are down to pressure evolved and time in barrel.

How much energy from the burning powder is transferred is a function of how much is lost at the muzzle, so slower heavier rounds can glean more from the same charge in the same barrel (as higher pressure is usually generated before it escapes). The longer the barrel vs the burn rate of the powder, the less difference there is in total energy transferred to a light bullet vs a heavy one.

While velocity weighs more into the KE equation, the INPUTS matter more, so those are what to look at for total energy available to deposit into a target.

This is validated by the large similarity in results between the massive variance in the bullet weight..

tl;dr: powder charge matters more than bullet weight for total KE. KE transfer into the target, that’s a different story.

The tests proved little or nothing as he should have tested a small diameter pistol bullet against the larger one. He did say he tested the .44 magnum previously but a head to head test would have been more informative. As long ago as 1900 it was well known both in testing pistols and in testing rifles that smaller diameter bullets with often their superior sectional density out penetrated much larger diameter projectiles even if both large and small bullets were traveling at the same velocity. Agnes Herbert who hunted with her Cousin on three continents stated that “the only advantage of the .450 elephant rifle was that if you wounded a big game animal that the bigger bullet left a bigger blood trail but when the animal was hit in a vital zone the smaller diameter bullet killed just as well and with her own 6.5 mm it always out penetrated her .450 elephant rifle. W.D.M.Bell had exactly the same results and he lived to tell about it after shooting well over 1,000 elephants.

In the Famous Thompson Tests of 1900 when the great Bull Shitter Col. Thompson tested various pistol calibers on live 1200 pound steers his own testing proved him wrong as he found that the smaller pistol calibers traveling at higher velocity out penetrated and killed the steers just as well as the slower moving larger pistol calibers. This he concealed from the ordinance board and he also deliberately quit testing the smaller caliber pistols when the tests were proving how wrong his big bore philosophy was. Even when he switched from solid large caliber bullets to expanding large caliber pistol bullets the large calibers failed to kill any better than the smaller pistol calibers. He states that the expanding bullets he used did indeed expand further proving how wrong he was in the statements he made to the ordinance board. The Neanderthal’s of the ordinance board bought the propaganda hook line and sinker and the rest is history as the U.S. then went on to adopt the .45acp pistol cartridge that was a horrendous military failure on number of counts.

The .45 acp in tests conducted in 1945 by of all people the U.S. Service horrified them when they found out that the .45acp bounced off of the military helmets they used in the test and the range was only 35 yards when the failures occurred. When the 9×19 was tested it penetrated the same helmet at an astonishing 125 yards and may have don so even farther but the accuracy and skill of the shooters forced the end of the testing which was more than conclusive enough anyway (see the book “The Ingles Diamond”).

In the famous “Pistolero Magazine Tests) of the 1980’s conducted in Mexico to get around animal cruelty laws it was found their was no difference in killing power between the .45 acp, 9×19, 38 Special and .357 Magnum when used at point blank ranges which are the rule in most pistol gun fights. As a note of interest they stated the hogs jumped higher and squealed louder when hit by the 9mm as opposed to the slower moving .45acp. Once again proving the 45 Acp Myth to be just that a contrived Myth that started way back in 1900 with Col. Thompson and lurid advertisement campaigns by the Colt Firearms Co. It worked like a charm back then and continues to work like a charm to the very day to people who do not bother to test pistol calibers on live animals.

As a side note I have shot very big White Tale Deer with the 9×19 (125 grain Remington expanding bullet) and the .30 Mauser pistol cartridge (85 grain bullet) and when vital organs were hit they fell down dead. A colleague of mine shot one White Tale Deer 6 times with a .45acp at very close range failing to knock it down. He then climbed down out of his tree stand and shot the animal point blank in the head. The weight bullet was a 185 grain expanding bullet which failed miserably.

There is some useful information in this post within the proper context. Yes, a smaller caliber bullet with the same mass as a larger caliber bullet will have a higher SD and potentially penetrate deeper than the larger caliber bullet of the same mass with all other things being equal. A heavier bullet with the same sectional density (ie more mass) than a smaller bullet driven at the same speed will penetrate deeper though.

Regardless, hunting stories are quite possible the worst way to judge bullet performance/lethality. I have shot a doe with my 308 that left a gaping silver dollar sized exit wound, center punched and jellied both lungs, tore a massive chunk out of the heart, and hydrostatic shock ruptured the diaphragm in multiple places, yet the deer ran nearly 50-75 yards as fast or maybe even faster than the other deer that were out in the clearing who scattered when the shot rang out. The exact same rifle and bullet has caused larger deer to go down as if struck by lightning with similar shot placement/ range etc. If your buddy shot the deer in the gut 6 times with a 45 and your 9mm scored a cns hit, then no shit yours was more effective, but as always, it depends on too many variables. The only reliable way to judge wounding effectiveness is in lab conditions with a standardized test media.

“Regardless, hunting stories are quite possible the worst way to judge bullet performance/lethality …. The only reliable way to judge wounding effectiveness is in lab conditions with a standardized test media.”

As an experimental scientist, I absolutely, unequivocally disagree with this statement.

Since there can be no lab test designed that mimics real tissue exactly or all of the various destruction mechanics and “psychological” effects of wounding, ALL the lab tests tell you is how a bullet performs in the lab tests. Nothing more than that. It is “improper” to extrapolate that to real tissue destruction in living animals.

The hunting results, on the other hand, take all the real world factors into account. That you see “failure” in one instance that you would forecast “success” simply shows you the uncertainty in your forecast model…that there is no 100% bullet | caliber | firearm, etc.

Lab tests can provide baselines, but over-control of the parameter space (that is, artificial reduction in dimensionality of the parameter space) will lead to false conclusions, incorrect models and at the end of the day….bad forecasts.

I forgot where i heard this but somebody somewhere said, given the same bullet construction, penetration depth in armor depends on energy density, while in flesh it’s momentum density. There’s gotta be a line somewhere separating the properties of the media to be penetrated.
Just sayin…

That’s pretty harsh, jlp. This was a fun, quasi-informative video. If you’ve got something better to contribute, buy some gel, shoot some guns, and fire up the camera. It takes a lot of time, money and preparation to make these vids.

his test proved exactly what he set out to test and prove weight vs speed of equal calibers on armor. Now I would like to see the test repeated on a whole hog (dead) with and with out the various pieces of ammo, to see how bad hard and soft armor will flail a ribcage, and as such kill the wearer anyway. Also both on un protected hogs to demonstrate the soft tissue damage. Gelatin seriously lacks when demonstrating hunting ammo.

Mass vs speed? I know light/fast 357’s are really effective at killing(125 grain). The same bullet in a 38 travelling at 4 or 500fps slower? Nope. A fast 9mm is way better than a 380-even with identical diameter. And the tiny necked down 243 is great for hunting…

thats why you compare similar to similar and caliber to caliber,,, and reduce variables. This plays right into the 9mm vs :any caliber here: arguement, when someone comes up with “but we have this bullet design” well dude, “so do we” or “we dont NEED it, your 9 still doesnt expand as wide as ours starts”… Too many people refuse to remove variables, and even in this test, he should have used 350 grain hard cast full wad cutters vs the 700 grain, round which is essentially a 700 grain full wad cutter… but the ammo was supplied for both from the same mfg… and 500 S&W mag ammo aint cheap, and we are not paying for his vids

It’s even more impressive against coons, skunks, and foxes. Underground Tactical made an integrally suppressed Ruger bolt gun with with this caliber and it is absolutely murderous on the varmints. So much fun at night.

Did the 700g bullet even stabilize properly? Without the correct rifling pitch rate who knows where the bullet will land.

There is a mathematical formula for determining rifling pitch rates. It’s called “The Greenhill Formula” which the manufacturers round down to the nearest appropriate number. It is better to have a rifling pitch that is faster or shorter than what is needed from the formula.

bullet weight on rifiling is actually a function of projectile length and twist rate. With that in mind the bullet will always land within the visual range of the bore for any given distance regardless of bullet stabilization, Simply put looking through the bore, you will have a tight cone of vision, getting larger the further away from the muzzle. regardless of rifling rate, the bullet will always land within the cone for any given distance. so your comment “who knows where the bullet will land” is ballistically wrong and outright foolish. The fact is rate of rifling becomes less and less critical the larger the projectile is. So were he comparing .22 Jet weights there would be greater discrepancies, but even then, they still would fall into the same “optical cone” as seen through the bore of the firearm.

I’ll raise you a highly asymmetric, lightweight bullet fired through a smoothbore…….
Would be cool if demolition ranch would do a video of bullets capable of boomeranging back to the shooter….

Also, at some distance, any bullet will fall below the sight cone through the bore.

Honestly, I cannot come up with any reason why the sight cone should have much effect on bullet trajectory, other than the completely obvious one. As long as a barrel shoots straight, making it longer doesn’t make it shoot straighter, despite it’s narrowing effect on the sight come.

Well due to the higher velocity, the “normal bullet” have about 25% more energy than the heavier, slower bullet. The heavy might look mean but higher energy usually wins, and higher speed usually gives some advantages when it comes to penetration.

no the formula is E= M C squared or energy = mass times speed times speed… HOWEVER this is purely empirical and the Taylor Knock out formula is more accurate since it also takes into consideration the cross sectional density of the round in transferring energy, rather than simply bleeding it off…
the formula is best viewed here even though I do not validate the site as reputablehttps://en.wikipedia.org/wiki/Taylor_KO_Factor

Not really referring to BULLETS>more weightlifting/jumping/throwing sports. But I’ll take fast and light over slow and big anytime. Except frangible crap. Big and fast is ideal. And I see you used MY 243 example…

So a lighter bullet traveling faster would improve the take-down (create more damage) in my .454 ? RSR w/ 7.5 inch barrel? I’ve seen 225gr ammo but have never used them thinking I need more weight for better take-down. If lighter and faster is better I guess I don’t really need the .454 I could use the 45 colt +P+ from the same gun and get better results? (take-down)

If you’re going for max penetration in game, the .45 caliber solids at a high weight and moderate velocity are the way to go. If you’re after “normal” big game like deer, JHP’s and JSP’s are the way to go.

Tim Sundles of Buffalo Bore and Garrett ammo offer some good explanations.

I shot a deer with a 240 grain XTP from a Ruger .454 with a 7.5″ barrel. That bullet left a baseball-sized hole through a 6 point buck at about 45-50 yards away. The round was from Hornady.

I foolishly traded in that revolver for a .460. Both the .454 and .460 have more than ample power on deer-sized game inside of 100 yards. Virtually anything in the 240-360 grain range will probably work just fine, but the 360’s have so much penetration that your round might pass through the first deer and hit another one.

what everyone is missing the fact that there is a point of balance, where the lighter faster round and the heavier slower round will reach a balance on kinetic energy. A prime example is the 5.56 x 45 round. extremely fast, but there are slower rounds such as the .243 Winchester, the 5.56 with 55 grains and the 243 with 105 grains are typically traveling in the area of 2800 fps but the .243 is still carrying more than double the power, were the bullet available in about 200 grains the 243 speed would drop to the point where both of them would have equal power. The point is speed and weight work together to develop the energy we use. when weight increases for a given caliber, we cant simply jack up the speed, as this would push the pressure level up. High pressure rounds lose accuracy, as well as create dangerous issues with the firearm itself coming apart and injuring or even killing the shooter. Something that the reason SAAMI specs were developed for

Actually, the 5.56 at 55 grains is about 3,250 fps out of a 20″ barrel, and around 3,100 fps out of a 16″ barrel. The 100 gr .243 is around 2,900 fps out of a full length barrel. The .243 doesn’t have double the energy of a 5.56, it’s actually about 50% more energy.

There is a big difference between fibrous tissue like wood, paper, kevlar on one side; and “liquids” on the other. In “liquids,” including gelatin and most living tissue, slower, heavier, bullets tend to penetrate farther.

Others have mentioned the 700 grainer possibly not being stabilized. If so, and it keyholed, that would definitely hurt penetration. Come to think of it, any yaw would almost certainly hurt penetration.

Well a 700 gr bullet key holing would be the ultimate hunting round if it was on target. Can you imagine the damage/wound channel? I’m amazed no one has made a “defensive” handgun/rifle or round that does this on purpose. Nasty. I’ll have to submit this idea for the .25 Poly-Raven w /rail and laser idea I had. 🙂

Don’t count on it. It may look impressive, but solid bullet hunters have for a long time realized the size of a bullet’s flat front, meplat, has a bigger effect than it’s largest diameter. And also that unstable bullets tend to weer away from harder, generally higher value, tissue. Most anyone I know with some experience, suggest by far the best performance from solids, is to have a wide meplat, remain stable, head first, and track straight regardless of tissue hit. The only time tumbling and yawing is beneficial, is if the goal is to limit penetration, and an expanding bullet is out of the question.